The Study On The Law Of Deep Fracture Developmentand Quantitative Evaluation Of Water Irruption Danger Of Group A Seam's Floor In Panxie Mining Area

Panxie Mining area belongs to the Huainan coalfield,geographical location is located in the north of Huaihe,the main coal mines?s production in Huainan and Xinji Mining Area are located in this area,most of the mine production level is above-800 m.The peripheral exploration area in Panxie Mining Area is deep exploration area.As the depth of the main coal seam is below-800m(We called the deep in this paper),the same primary mineable coal beds there are deeper than other coals in Panxie Mining area,the deep is the main research object in this paper.Comparison with shallow coal seams(above-800m),the geological and hydrogeological conditions in The Deep are more complex.It is mainly characterized by high stress characteristics and high pressure water characteristics.The characteristics of the development of the fracture of the rock determined the water rich regularity.In the deep group A,the hydrogeological condition of the coal mining is obviously different from that of the shallow coal mining.As the depth of coal mining in Panxie is getting deeper and deeper,It is very important for the safe mining of coal minings to analyze and appraise the characteristics of fracture development of the primary mineable coal beds and water irruption danger of group A seam floor in the deep.On the basis of data collection of Panxie Mining Area exploration,production and extension of deep exploration area,we analyzing and evaluating the geological and hydrogeological conditions?fracture development characteristics of the roofs and fioors of main coal seams?the law of ater rich regularity in karst aquifers.And based on this,the evaluation was carried out about the water abundance in karst strata and water irruption danger of group A seam floor.The main results are as follows:(1)The characteristics of fracture development are mainly reflected by the weighted RQD of the top and floor of the main coal seams,the consumption of flushing fluid,and the shale content retrieved from the logging curve.The results show that: in vertical direction the fracture development degree in the deep has gone worse or got worse or got better as depth increased;(2)The water rich regularity of limestone is reflected by the relationship about the depth of limestone aquifer,specific capacity,permeability coefficient and the water pressure.And use the Analsis Hierarchy Process(AHP)to evaluate the water rich regularity of limestone.The results show that: for limestone aquifer of Taiyuan group,due to the characteristics of its high water pressure,and has a hydraulic connection with the limestone aquifer of Ordovician system,it has become one of the main water filling sources of mine water damage with a poor water rich character.But the water abundance of limestone aquifer of Ordovician system has great difference;(3)The analysis and evaluation of the water irruption danger of group A seam floor by the vulnerability index method of GIS and AHP coupled.The results show that: The water irruption danger of group A seam's floor represented that the relative safety zones are mainly distributed in the southern part with maximum area,the more safe areas are distributed in the middle with not large area,other fragile,vulnerable and transitional areas are distributed in the northern part with the least area.